1. Field
This invention has to do with the forming of a simulated ornamental stone, such as marble or onyx, in a mold utilizing a polyester resin or the like along with other materials to provide veining and back-up matrix therefor.
2. State of the Art
Simulated marble has long been produced commercially by a process disclosed by K. A. Starr et al. in U.S. Pat. No. 3,773,886. An improved procedure is disclosed by James C. Sheridan in U.S. Pat. No. 4,248,816. Both procedures use a mold and a polyester resin or the like mixed with a catalyst and various other materials to provide a relatively thin gel coat covering the mold surface, veins superimposed on the gel coat, a layer of spatter superimposed on the veins and providing a multiplicity of voids to provide visual depth, and a back-up matrix to fill the mold. Sheridan uses multiple layers of spatter, one layer covering the voids of another layer to provide increased visual depth. Both mix a volatile solvent, a vinyl monomer, and a rubbery material with the polyester resin for the veins and the spatter, which are sprayed or otherwise made to fall through the air during application, so solvent will evaporate as the material falls into place. A matrix material, again polyester, a catalyst, and calcium carbonate as a filler, is used as an uncolored, opaque back-up material to fill the mold.
Simulated onyx has also been produced commercially using alumina trihydrate as a translucent filler material instead of calcium carbonate.
3. Objective
A principal objective in the making of the present invention was to provide a more realistic synthetic stone product having greater depth of color and an overall more attractive appearance.